Ceramic Light-Emitting Device Joining Material Reflectance

Solution Overview

Problem

Conventional light-emitting devices with glass tubes face challenges in miniaturization, leading to decreased light emission due to absorption of light by joining materials when a package and light transmitting member are joined.

Innovation Solution

A light-emitting device with a ceramic package and a light transmitting inorganic member joined via a joining layer made of glass and oxide ceramic powder, which includes alumina powder to enhance reflectance and reduce light absorption, while maintaining airtightness and supporting miniaturization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a package and light transmitting member are joined via a joining material, then the device can be miniaturized, but the light emission amount decreases due to light absorption by the joining material

Engineering Contradiction:

Improvedevice sizeVSAvoidlight emission amount

Core Design Contradiction:

Volume of moving objectVSIllumination intensity

Solution Approach 1:

The joining material is designed to have a white color with high light reflectance by incorporating oxide ceramic powder (such as alumina, zirconia, or titania) into the glass matrix. This color modification approach transforms the joining material from a light-absorbing component to a light-reflecting component, thereby resolving the contradiction between miniaturization and light emission maintenance.

Inventive Principle:

Principle #32Color changes

Solution Approach 2:

The joining material is formulated as a composite consisting of glass (for airtightness and bonding) and oxide ceramic powder (for high reflectance). This composite structure combines the advantages of both materials: the glass provides sealing and adhesion functions, while the ceramic powder particles dispersed within the glass matrix provide high light reflectance, thus maintaining light emission while enabling device miniaturization.

Inventive Principle:

Principle #40Composite materials

2Volume of moving object

If the device is miniaturized, then it can be mounted on portable terminals, but the light emission amount decreases

Engineering Contradiction:

Improvedevice sizeVSAvoidlight emission amount

Core Design Contradiction:

Volume of moving objectVSIllumination intensity

Solution Approach 1:

The joining material, which necessarily exists and occupies space in the miniaturized device structure, is transformed from a harmful light-absorbing element into a beneficial light-reflecting component. By incorporating high-reflectance oxide ceramic powder, the joining material now contributes positively to light emission, converting the unavoidable presence of the joining material in miniaturized designs into an advantage that maintains or even enhances light output.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Device complexity

If a joining material is used to join package and light transmitting member, then the structure is simplified, but light is absorbed by the joining material

Engineering Contradiction:

ImprovestructureVSAvoidlight emission amount

Core Design Contradiction:

Device complexityVSIllumination intensity

Solution Approach 1:

The joining material is designed to have a white color with high light reflectance by incorporating oxide ceramic powder (such as alumina, zirconia, or titania) into the glass matrix. This color modification approach transforms the joining material from a light-absorbing component to a light-reflecting component, thereby resolving the contradiction between miniaturization and light emission maintenance.

Inventive Principle:

Principle #32Color changes

Solution Approach 2:

The joining material is formulated as a composite consisting of glass (for airtightness and bonding) and oxide ceramic powder (for high reflectance). This composite structure combines the advantages of both materials: the glass provides sealing and adhesion functions, while the ceramic powder particles dispersed within the glass matrix provide high light reflectance, thus maintaining light emission while enabling device miniaturization.

Inventive Principle:

Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively suppresses the decrease in light emission by improving reflectance and maintaining airtightness, allowing for efficient light transmission and emission, while enabling the miniaturization of the device.

Implementation Method 1

the joining material including glass exhibiting a white color, and oxide ceramic powder

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 2

an inert gas encapsulated inside the discharge space; and a couple of discharge electrodes which are disposed in the depressed portion of the ceramic package so as to be spaced from each other

Methodology Applied

Scientific EffectElectric discharge: Electric Arc

Data Source

PatentUS9892904B2Light-emitting device

Publication Date: 2018.02.13 KYOCERA CORP

AI summary

There is provided a light-emitting device capable of suppressing a decrease in a light emission amount. A light-emitting device including a container member including a ceramic package provided with a depressed portion serving as a discharge space, and a light transmitting member which is attached to the ceramic package via a joining layer formed of a joining material so as to close the depressed portion; an inert gas encapsulated inside the discharge space; and a couple of discharge electrodes which are disposed in the depressed portion of the ceramic package so as to be spaced from each other, the joining material including glass exhibiting a white color, and oxide ceramic powder.